
#include <stdio.h>
#include <assert.h>



char* my_strcat(char* arr, const char* arr2)
{
	char* ret = arr;
	assert(arr && arr2);
	
	while(*arr != '\0')
	{
		arr++;
	}
	while(*arr++ = *arr2++)
		;
	
	
	return ret;
}



int main()
{
	char arr[20] = "hello ";
	my_strcat(arr, "world");
	
	printf("%s\n", arr);
	
	
	return 0;
}


